Furnace-grate.



C. B. ROBERTS.

FURNACE GRATE.

APPLICATION FILED APR. 6 19l4.

1,138,978. Patented May11,1915.

WAMHNGION, D C.

1U NEVE@ @TATES Re.

naar erraten CLAUDE B. ROBERTS, `GJ? BELFAST, MA32h32@,`

FURNACE-GRATE.

Application led. April 6, 1914. Serial No.7829,9l8.

T0 all 107mm it may concern.'

Be it known that l, CLAUDE B. ROBERTS, a citizen of the United States, residing'at Belfast, in the county of lValdo and State of Maine, have invented an Improvement in Furnace-Grates, of which the following is a specification.

This invention relates to improvements in furnace-grates especially designed for burning :#3 hard coal or liner or even sludge, with a forced draft.`

rlhe object of the invention is the construction of the grate-sections which are or may be arrangedtransversely on bar carriers borne by a pair of moving chains, which grate-sections have openings and channels so formed and arranged relative to each other that coal of said degree of fineness may be burned, and a very high etliciency and rating obtained.

ln one complete embodiment of my invention the grate consists in a plurality of grate-sections arranged in connection with transverse bar-carriers borne by moving chains, such for instance as are commonly employed in a mechanical stoker, which grate sections are curved from end to end and have openings through them, arranged in parallel vertical planes, with diverging walls extended from top to bottom or thereabout, said openings being of the shape of a Greek cross, which openings are arranged in rows and the openings of the several rows are staggered with respect to each other, thereby to provide for maximum air admission and distribution as compared with the total areas of the sections, all as shown in an application for Letters Patent I #829,917, iiled April 6, 1914;, `and the top surfaces of said grate-sections are formed with channels between and in open' communication with the aforesaid openings which permit of the freeV and unobstructed passage of air between the opening and over the exposed portion of the fuel-bed, and said channels in connection with said openings form flat surfaced projections of rectangular outline, in plan, which projections cause the fuel to travel at a slow rate of speed by and with the grate, without slipping. As the edges of the projections burn away the air admission and distribution is not eifected until they have burned far enough to increase the size of the openings at the top, although during this time said projections become more and more spherical, yet fuel economy is not reduced until the sizes of the openings at the top havebegun to enlarge. v j

Figure 1 is a plan view ofa grate-section embodying this invention. Fig. 2 is a longitudinal vertical section of the same on the dotted line 2 2, Fig. 1. Fig. 3 is a plan view of the several grate-sections arranged in grate-forming relation on moving chains. Fig. l is a detail of a portion of the grate in side elevation.

rllhe grate sections 1, as here shown, are of rectangular outline, in plan, and curved transversely7 on the arc of a circle, and have at each end downwardly extended portions 2 arranged with recesses 3, adapting them to be arranged on transverse bar-carriers l, which are borne by moving chains 5, and

said sections have at one end a downward and outward extended lug 6 arranged to enter an undercut portion 7 at the opposite end lof an adjacent grate-section. Each grate-section has openings 10 through it from top to bottom, which openings are of the form of a Greek cross, thereby Colnprising a plurality of narrow elongated portions, radially arranged and merged together, and while each opening is of large area yet #-3 or liner coal or even sludge will not pass through it, thus permitting of the burning of coal of such degree of fineness. These openings are arranged in rows and the openings of each row are staggered with respect to each other, as represented in Fig. 1, and by such arrangement the aggregate area of the openings for the admission and Vdistribution of air is very large as compared with the total area of the grate-section. These openings are formed with diverging walls extending from top to bottom or thereabout and they are arranged in parallel vertical planes, thus admitting of the air increasing in velocity as it enters the fuel-bed and the ash falls straight downward from said bed. On top of the gratesection channels 12 are formed which are likewise made in the form of a cross comprising elongated narrow portions of the same width as the narrow portions at the top of the openings, and said channels are in open communication with said openings, extending from one to another, as represented in Fig. 1. These channels admit of the free circulation and distribution of air from all the exposed portions of the fuel-bed and leading as they do from one sov become choked. These channels l2 are arranged in open communication with the openings 10l and result in the formation of projections 14 on the top .surface of the grate-section of rectangular outline in plan,

and these projections serve the purpose of causing the fuel to travel with and by the grate-section at a slow rate of speed with.- out slipping. As the edges of these projections burn away the air admission is not effected until they have burned Jfar enough to enlarge the openings 10 at the tops, although during all of this time said projections becoine gradually more and more spherical' by the rounding off of the corners, which does not eect the fuel economy'until they haveburned away far enough to enlarge the openings at the top.

l claim l. A grate-section having means for attaching it to a transverse bar-carrier borne by moving elements, said grate section having openings through it of the Jform of a Greek cross, which openings are arranged in rows, the openings of each row being staggered with respect to the openings of adjacent rows, said grate-section also having channels at the top arranged in open communication with saidy openings, substantially as. described.

2. A grate-section having means for attaching it to a transverse bar-carrier borne by moving. elements, said grate-section having openings through it of the form of a Greek cross, which openings are arranged in rows, the openings of each row being staggered with respect to the openings of vadjacent rows, said grate-section also having intersecting channels at the top extending from end to end and from side to side of the section, which channels are in open communication with the adjacent openings, substantially as described.

A grate-section having means for attaching it to a transverse bar carrier borne by moving elements, said grate-section having openings through it of the forni of a Greek cross, which openings are arranged in rows, the openings of each row being staggered with respect to the openings of adjacent rows, said grate-section also having projections at the top between the openings which projections are of rectangular outline in plan, substantially as described.

` A grate-section having means for attaching it to a transverse bar-carrier borne by moving elements, said grate-section having openings through it of' the form of a Greek cross, which openings are arranged in rows, the openings of each row being staggered with respect to the openings of adjacent rows, said grate-section also having channels at the top arranged in open communication with said openings, said channels in communication with the openings forming projections of rectangular outline in plan, substantially as described.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

CLAUDE B. ROBERTS. Witnesses:

W. N. CORGILL, H. C. DRowN.

Copies of this patent may 'be obtained for ve cents each, by addressing the Commissioner* of Patents, Y Washington, D.' C. 

